Physics practical

Question 1

describe specific heat Capacity

Answer 1

The specific heat capacity of a substance is the amount of energy required to raise the temperature of 1kg of a substance by 1 degree

Question 2

specific heat capacity practical

Answer 2

• Place beaker on balance and press zero
• Add liquid (e.g oil) to beaker and record mass of liquid from balence
• Place a thermoneter and immersion heater into the oil
  -Read starting temperature of the oil
  -Wrap beaker in insulating foam to reduce thermal energy transfer to surroundings
• connect a joulemeter and powerpack to immersion heater (joulemeter tells us how many joules of electrical energy pass into immersion heater)
• Leave set up for 30 minutes (allows temp to rise accurately enough so we can read on thermometer)
  -read final temperature of liquid (oil)

-Calculate SHC with equation

-

Question 3

Sources of inaccuracy in the Specific heat capacity and how to fix

Answer 3

• Thermal energy passing out of the beaker into the air
  -Solve this by using a insulator with a lower thermal conductivity

-Not all thermal energy passing through the oil.
-Ensure emersion heater is fully submerged

Incorrect reading on thermometer
- Use electronic temperature probe

Question 4

Describe how to investigate the effectiveness thermal insulators

Answer 4

Place small beaker inside a larger beaker
- Boil water with kettle
-Transfer 80cm^3 of hot water into the small beaker
- use a piece of Carboard as a lid for the large beaker
- lid must have a hole for the thermometer
- we place thermometer through hole in the carboard lid
- bulb of thermometer must be in hot water
-we record starting temperatures of the water and start a stopwatch
- Record temperature of the water every three minutes for fifteen minutes
- Repeat experiment using same volume of hot water
- However, this time we use an insulating material (eg) bubble wrap to fill the gaps between the two beakers.
- Test range of different insulating materials. For example, cotton wool and polystyrene balls.
- Use same mass of insulating materials in each case

Question 5

variables for Thermal insulators practical

Answer 5

independent variable - Type of insulating material

dependant - one that is measured for change each change in the independent variable e.g temp

Control - variables we do not allow to change. volume of water, mass of insulating and starting water temp.

Question 5

Reflection and Refraction practical

Answer 5

• place a glass block on a piece of paper
• draw around the glass block
• use the ray box to shine a ray of light through the glass
  block
• mark the ray of light entering the glass block
• mark the ray of light emerging from the glass block
• join the points to show the path of the complete ray through
  the block
• and draw a normal line at 90 degrees to the surface
• use a protractor to measure the angle of incidence
• use a protractor to measure the angle of refraction
• use a ray box to shine a ray of light at a range of different
  angles (of incidence)
• increase the angle of incidence in 10 degree intervals
• from an angle of incidence of 10 degrees to an angle of
  incidence of 80 degrees